Thread-controlling mechanism for overedge sewing machines



Oct. 22, 1940. N K ETYAL 2,213,796

THREAD-CONTROLLINGMECHANiS LLFOR OVEREDGE SEWING MACHINES FiledJQly 15/1939 6 Shets-Sheet z 7 W Perc ival (l/Inion Oct; 22, 1940;"

N. KNA'us-"E AL THREAD-CONTROLLING MECHANISM FOR OVERE'DGE SEWING MACHINES 5 'SheetS-Shet 3 Filed July 15, 1939 6 W n w m ww w? i? a 1 Z MM NW Oct. 22, 1940. KNAUQ ET AL 2,218,796

OVEREDGE SEWING MACHINES THREAD-CONTROLLING MECHANISM FCR Filed July 15, 1939.

f '6 Sheets-Sheet 4 Nichola/us Ii'rzaua mod Percival cl/Inion W%QM Get. 22, 1940.

N. KNAUS ET AL 511 FUR OVEREDGE SEWING MACHINES THE EAD-C ONTROLLING "MECI'IZ-ENZ 6 Sheets-Sheet V Filed July 15, 1939 JHQ: M

I Oct. '22, 1940. 1 N, KNAUS ET A 2,218,796

THREAD-CONTROLLING MECHANI 55.1 FOR OVEREDGE SEWING MAC'rIINBS Filed July 15, 1959' 6 Sheets-Sheet 6 Patented Oct. 22, 1940 UNITED STATES PATENT OFFICE 'rnamn-courasfi rmommsM For.

Nichola'us 'KnausyNewark, and Percival J. An-

ton, Elizabeth; N. J., assignors to The Singer Manufacturing Company,Elizabeth, N. .L, a corporation of New Jersey Application July 15, 1939. Serial No 284,628

13 Claims- (Cl. lie-162i This invention relates to overedgesewing machines, moreparticularly of the type disclosed in the copending application of Nicholaus Knaus, Serial No. 278,393, filed June 10," 1939.

The invention has'for .an object to provide the machine with a simplified and efficient thread-controlling mechanism which is adaptable to stitching requirements onvarious materials, as well as meeting the requirements for 10 sewing an elastic chain in the vair in" c'haln'- lng off" operations.

With the above and other objectsinfview, as will hereinafter appear, the inventioncomprises the devices, ,combinations, and arrange l5 ments of parts hereinafter stiorthandillustrated in the accompanying drawings of 'a preferred embodiment of the.invention,' from which" the several features of t he"inventi on and the advantages attained thereby willbe readily un- 20 derstood'by those skilled in the a I In the accompanying drawings, Fig. 1 is a front'side elevation of an overedge sewing Ina-- chine embodying the invention. Fig. 2 is a lon gitudlnal vertical section through the machine 25 frame. Fig. 3 is a bottom plan view of the machine. Fig. 4 is a stitching end elevation of the machine. Fig. 5 is a view of the needle, looper and needle-thread guiding parts of Fig. 4,with the needle all the way down. Fig. 6 3 is a perspective view of a work-sample sewed on the machine. Figs. 7, 8, 9, 10 and 11 are a series of views of the stitch-forming and threadhandling devices at diflferent consecutive timepoints of a stitch-forming cycle. 35 As disclosed in said Knaus copending application the machine is constructed with a frame in the form of a hollow casing I closed at the bottom by the base-plate 2. Journaled in the frame casing l is the main shaft 3 formed with the three cranks 4, and 6 which drive the under looper I; the needle 8 and the overedge looper 9, respectively.

The curved needle 8 is carried by the arm ill of the rock-shaft H journaled in the frame bushing l2, Fig. 2, and carrying at its inner end the crank-arm [3 .which is connected by the pitman l4 with the actuating crank 5. The under looper I is carried by the rock-shaft ii to which is fixed the hub i6 of the crank-arm l1 ac- 50 tuated by the pitman l8 and its actuating crank 4. The carrier lever IQ for the overedge looper 9 is pivoted at 20 to a sleeve 2| which is slidably supported by the pin 22 carried by the frame I. The lever i9 is pivotally connected at 55 23 to an arm 24 fixed to the rock-shaft 25 which carries the inner crank-arm 26 actuated by the pitman 21 and crank 6.

Mounted for rotative adjustment in the frame I is a needle-thread guide-tube 28 having at its delivery end an arm 29 formed at its free end 5 with a thread-guide eyelet 30. The needle-carrying arm [0 has a V-notch 3i in the front side of the needle-clamp at its free end to deflect or bend the needle-thread t forwardly when the needle approaches the lower limit of its stroke. See Figs. 4 and 5. This bending of the needlethread t has a stitch-tightening and pull-off action which is 'regulatable by turning the tube 28 in the frame I, Fig. 2, about its longitudinal axis to carry the thread-eye 30 forwardly or backwardly, Fig. 5,-about the axis of the tube 28.

Fixed to the under-looper rock-shaft i5 is a thread take-up arm 32 having two spaced forwardly projecting arms 33, 34 having threadeye'sat their free ends. The arm 33 projects through a slot 35 in the plate 36 while the arm 34 projects through the slot 31 in said plate.

Mounted in a circular hole 38 in the plate 36 for pivotal adjustment is the cylindrical hub 39 of a stationary thread-guide arm 40 having at its free end a thread-eye. The tail 40 of the thread-guide arm 40 is threaded to receive the clamp-screw 4| which passes through the arcuate slot 42 in the plate 36.

Fixed to the rock-shaft 25 is a thread takeup arm 43 which terminates in the hook 44 Working between the thread-arms 33 and 34. The plate 36 carries the vertically adjustable guide 45 for the under-looper thread u. The threadguide 40 is disposed between the take-up eye 34 and the take-up hook 44 and guides the overedge thread 0 only.

The thread it runs from the supply through the tension-device 46 and thread-guide 45 to and through the eye in the thread-arm 34, thence under the hook 44 and through the eye in the thread-arm 33. From the eyed arm 33 the thread u runs through the horizontal guide tube 46 and vertically in the slot 41 to the guide tube 48 through which the thread runs to the eye of the looper 1.

The overedge looper-thread 0 runs from the supply through the tension-device 49 and threadguide 50 to the circularly adjustable guide 40, thence under the hook 44 and through the eyed 50 guide 33 to the thread-tube it through which the thread 0 runs to the overedge looper 9.

Operation Starting with Fig. 7, as the needle 8 rises to throw out its thread-loop 52, the needle-thread t, which is under a stitch-tightening strain when the needle is at the bottom of its stroke, is immediately slackened by retraction of the needlethread stitch-tightening notch 3| in the needle-carrying arm ID. The under looper 1 advances oii'fa slack Qhread 52. The take -fip arms- 33 as the looper I advances and give up slack thread to the advancing under looper. There is very little movement of the overedge looper 9 and take-up hook 44 as the under looper fliadvances.

When the under looper its advancing stroke, the needle-point-iswrising from the goods53 and the-point of'the overedge looper 9 rises to the under looper, as shown in Fig. 8. As the overedge looper 9 rises, the thread take-up hook 44 rises and gives slack to the thread 0. The rising guide 33 slides up-on thethread between the tube and hook M, Fig. 9, and. the rising guide 34 is not.

engaged by the. thread 0,. Thus, slack-thread o is. supplied for the overedge looper torise with, and the looper -I retracts leaving a looper-thread loop 54.011 the overedge looper 9. The needle reverses its motion atthe upper end of its'stroke and takesa loop 55 of thread 0 from the overedge looper-.9 as the latter retracts to shed the loop-.54. After. the loops 52 and. 54 are shed,

the down motion .of the take-up book 44 tightens both threads u and 0, particularly the thread u, and draws up the loops 54 and 55 .so that they lie snugly in place on the work or stitch-finger ;of--the machine when no ,work is being sewn.

The descending needle andnotch 3i also tighten the previous needle-thread loop 52 shed by the retracting .under Y looper "I. This completes a stitch-forming cycle. U

By adjustingthe thread-guide 40 upwardly, the take-up-action of the falling guide-hook 44 on the thread 0 only is increased and vice versa. The take-up action'oi the eyed-arms 33 and 34 on the thread u only may be modified by ver-- 'tical adjustment of the guide 45.

By the means provided it is possible to control'the' threads and draw up and properly set the stitch in also possible to sew an elastic chain in the air, as shown in Fig. 6, in which the needlethread tis'n'ot drawn tightly and runs over and under the threads 0 and u, respectively, in a serpentine course giving longitudinal" elasticity to the chain.

Having thus set forth the nature vention, what we-claim herein is:

1. A sewing machine having an endwise reciprocatory needle, an under looper and an overedge looper; a; pair of spaced parallel rock-shafts each connected to actuate a respective one of said loopers; looper-thread take-up arms carried by said rock-shafts and extending toward one another for action on the looper-thread, and means to guide alooper-thread to a position of the in- 1 within the range of action of-said take-up arms. 2. A sewing machine having an endwise reciprocatory needle, an under looper and an overedg'e looper, a pair of rock-shafts each connected to actuate a respective one of said loopers, a

double-eyed take-uparm carried by one of said rock-shafts; and a take-up :arm carried'by'the.

other 0: .said rock-shafts and having a threadengaging portion working in the space between the eyes of said double-eyed take-up arm.

3.'A' sewing machine having an endwise reand takesthe loop.- and"34 are dropping.

. edge looper,

I reaches'the' end of take a thread-loop from i along and does nottake- -thread engaging and a 'wide variety of vmaterials. It is ciprocatory needle, an under looper and an overedge looper, a pair of rock-shafts each connected too actuate a respective one of said loopers, a slotted plate, and looper-thread take-up arms carried by said rock-shafts and having threadengaging terminal portions extending through said slotted plate... I

4.-A'se wing- 'aehine having Tan endwise reciprocatory needle, an under looper and an overa pair of rock-shafts each connected to actuate a respective one of said loop- .ers, 'a slotted'plate, looper-thread take-up arms carried by said rock-shafts and having thread- -engaging. terminal portions extending through --said slotted plate and a pair of adjustably positioned stationary thread-guides on said plate for --the respective looper-threads.

5. In an. overedge, sewing machine, a curved needle, 9. needle-carrying arm having a needlebending portion, a rockshaft carrying said arm, and a needle-thread guide between which and the'needle the thread sewing machine, a curvedisengaged and bent by said arm as the needle thread engaging and bending portion, a' rock- I shaft carrying said arm; and an adiustably positioned needle-thread guide between which and the needle,.the' thread is engaged and bent by said arm as the needle approachesthe' end of its work penetrative thrust. T

7. Inan overedge se ng machine, a curved needle, 8. needle-carrying ar'm having aneedlethread engagin and bending portion, a rockshaft carrying saidarm, a 'rotatably adjustable needle-thread-guiding"tube, and a thread-guiding. arm carried by said tube and having-a guideeye offset, from the axis of. said tube to soflead the thread to the needle that the threadwill be engagedand bent bysaid needle-carrying arm as theneedle approaches the end of its workpenetrative thrust.

.8. A sewing machine having an endwise re-' ciprocatory needle, an under looper and an overedge looper, a pair of rock shaft's each connected to actuate.a respective one of said loopers, a thread take up arm secured to' one of said rockshaftsand having two eyed lateral extensions, and a thread take-up arm secured to the other of said rock-shafts and having a lateral extension positioned to engage a looper-thread between the eyed lateral extensions of the first mentioned thread take-up arm.

9 ..A sewing machine having an 'endwise reciprocatory needle, an under looper and an overedge looper, a pair of rock-shafts each connected to-actuate a respective one of said loopers, a looper-thread take-up arm carried by each of said rock-shafts for simultaneous cooperative action on the same looper-thread, and means to guide a looper-thread within the range of action of both of said take-up arms.

10. A sewing machine having a main shaft formed with three cranks, a needle-operating rock-shaft driven by one oi said cranks, an under looper operating rock-shait'driven by another of said cranks, an pveredge looper operating rock-shaft driven by the third one of said cranks, needle-thread stitch tightening means carried by said needle-actuating rock-shaft,'and looperthread stitch-tightening means carried by said looper-operating shafts.

,11. A sewing machine having a main shaft formed with three pranks, a needle-operating rock-shaft driven by one of said cranks, an under looper operating rock-shaft, driven by an- 'other of said cranks, an overedge looperoperby said looper-operating rock-shafts, said means I being timed to exert their stitch-tightening actions substantially simultaneously at a period of the stitch-forming cycle when the needle is approaching the end of its work-penetrative thrust after the under looper-thread loop has been shed by the retracting overedge l'ooper and after the needle-thread loop has been shed by the retracting under looper.

12. An overedge sewing machine having a needle, an under looper, an overedge looper, a slotted plate, vibratorylooper-thread take-ups extending through said slotted plate, and stationary looper-thread guides adjustably mounted on said plate.

' 13. An overedge sewing machine having a needle, an under looper, anoveredge looper, a slotted plate, vibratory looper-thread take-ups extending through said slotted plate, and stationary looper-thread guides adjustably mounted on said plate, one "of said adjustable stationary guides being disposed between two of said vibratory looper-thread take-ups.

- NICHOLAUS KNAUS.

PERCIVAL J. ANTON. 

